*{
    margin: 0;
    padding: 0;
}
.box{
    margin-top: 50px;
    margin-left: 40%;
}
.h,
.m,
.s{
    width: 50px;
    height: 50px;
    border: 1px solid;
    background-color: aquamarine;
    margin-left: 10px;
    float: left;
   
}
.h::after,
.m::after,
.s::after{
    content: '';
    font-size: 30px;
    margin-left: 33px;
}
